Automotive instrument clusters typically comprise large discreet display areas for a speedometer and a tachometer, and a number of smaller displays for coolant temperature, oil pressure, oil temperature, fuel level and the like. Arranged within and around the cluster are other indicators showing low fluid level conditions, turn signal operation, emergency light blinkers and so forth. The analog displays within the display fields are provided by means of devices having electromechanical movements for causing angular sweep of a needle across the display field. In American systems, low values of the measured quantity are typically displayed at the left side of the display field, high values at the right side of the display field, and intermediate values at incrementally spaced locations between the left and right sides.
It has become increasingly more difficult to attach cables, wires and other devices to the back side of the instrument cluster to provide all of the various desirable displays while retaining flexibility and accessability. Moreover, all of the meter movements are difficult to calibrate and to maintain in calibration.
The prior art patent to Brooks U.S. Pat. No. 4,761,715 “Laser Pointer,” issued Aug. 2, 1988, shows how an analog instrument and/or a combination of analog instruments can be implemented using a light source to provide an illumination marker. The Brooks patent, however, uses a meter movement which is presumably galvanometric or step-motor-operated to rotate a laser beam from a diode laser, the degree of clockwise rotation corresponding to values of various measured quantities.